1. Field of The Invention
The invention relates to a method of opening a package including a content wrapped with a wrapper. The content may comprise a roll including a web of paper wound thereon to form multi-layers, or sheets of paper stacked into multi-layers. The web or sheets may be adapted to be printed or converted. In addition, the invention relates to the structure of the package. The invention further relates to an apparatus for opening the package.
2. Description of Related Art
There has been generally used a roll R including a web of paper wound thereon to form multi-layers, for example in a web-fed press for newspaper or magazine, as shown in FIG. 35 and FIG. 36. The roll R is wrapped with a wrapper W for transportation and storage to form a package P including the roll R therein. The wrapper W keeps the roll R from being damaged. Accordingly, first of all, it is required to cut the wrapper W circumferentially of the package P at the opposite end portions thereof and then cut the wrapper W axially of the package P, to open the package P. The roll R is taken out of the package P and mounted on the web-fed press. The web of paper is fed from the roll R and printed by the web-fed press.
As to the operation to open the package P, it is conventional to manually cut the wrapper W with a knife and a bamboo spatula. An operator manipulates the knife at the opposite end portions of the package P to cut the wrapper W circumferentially of the package P. The operator then inserts the bamboo spatula between the wrapper W and the roll R at one of the opposite end portions of the package P and move the bamboo spatula axially of the package P, to cut the wrapper W axially of the package P.
However, the roll R is very heavy. In addition, the wrapper W generally comprises a wrapping paper which is durable and strong. The wrapping paper is closely fitted on the outer surface of the roll R. It is therefore troublesome to manually and conveniently cut the wrapper W with the knife and the bamboo spatula. Labour and time are required. It has also a problem that the roll R may be damaged by the bamboo spatula inserted between the wrapper W and the roll R and moved axially of the package P. It is a task of extreme difficulty to manually and conveniently cut the wrapper W to open the package P, without damage of the roll R.
There has been heretofore proposed an apparatus for automatically cutting the wrapper to open the package, as disclosed in Japanese Laid-Open Patent Publication No. 311,438 of 1992. The apparatus includes a knife having a portion of T-shaped cross section and equipments for inserting the knife between the wrapper and the roll and moving the knife axially of the package, to cut the wrapper axially of the package. However, the equipments are complicated and expensive. It takes much time to open the package. It has also a problem that the knife is liable to be worn and damaged by the durable and strong wrapping paper. It is therefore required to frequently exchange the knife for new one.
There has been also used sheets of paper stacked into multi-layers, in the sheet-fed press. The sheets are wrapped with a wrapper for transportation and storage to form a package including the sheets therein, like the roll of web. Accordingly, it is required to cut the wrapper to open the package.
As to the web and sheets to be converted by a paper converting machine, it is also required to cut the wrapper to open the package.
It is therefore an object of the invention to provide a new and improved method of opening a package including a content wrapped with a wrapper, and an apparatus therefore, to thereby overcome the above problems.
Another object of the invention is to conveniently cut the wrapper and open the package, without damage of the content.
Other object of the invention is to conveniently cut the wrapper and open the package, without complicated and expensive equipments.
Other object of the invention is to conveniently cut the wrapper and open the package, without taking much time.
Other object of the invention is to conveniently cut the wrapper and open the package, without the problem relating to the wear and damage of knife.
According to the invention, there is provided a method of opening a package including a content wrapped with a wrapper. The method comprises the step of directing a laser beam to the wrapper for cutting the wrapper with the laser beam to open the package. The method further comprises the step of protecting the content from being damaged by the laser beam.
There is also provided a package to be opened. The package comprises a covering layer of material having a laser beam absorptivity which is lower than that of the wrapper. The covering layer is interposed between the wrapper and the content for covering the content from the laser beam to protect the content from being damaged by the laser beam.
The material may be coated on or impregnated into the inner surface of the wrapper to form the covering layer.
The material may be coated on or impregnated into the outer surface of the content to form the covering layer.
In other embodiment, the content is of multi-layers. The covering layer is interposed between the layers of the content adjacent to the outer surface of the content for covering the content from the laser beam to protect the content from being damaged by the laser beam.
In the embodiment, the material may be coated on or impregnated into at least one layer of the content adjacent to the outer surface to form the covering layer.
The content may comprise a roll including a web of paper wound thereon to form multi-layers, or sheets of paper stacked into multi-layers. The web or sheets may be adapted to be printed or converted. The wrapper may be made of paper, plastic film or fabric.
The covering layer may be formed of a foil of metal.
The covering layer may extend substantially all over the circumference of the content.
The covering layer may comprise an elongated strip. The package may be intended to cut the wrapper with the laser beam along the strip.
In other embodiment, the step of protecting the content comprises the step of utilizing a type of laser beam not capable of cutting the web or sheets. The wrapper comprises a wrapping paper having a laser beam absorptivity which is higher than that of the web or sheets with respect to the type of laser beam to cut the wrapping paper and open the package with the laser beam.
In the embodiment, the wrapping paper may include a material admixed thereinto and having a high absorptivity with respect to the type of laser beam.
The method may further comprise the step of moving the package relative to the laser beam.
In a preferred embodiment, the package is cylindrical. The step of moving the package comprises the step of rotatingly moving the package about the central axis thereof for cutting the wrapper circumferentially of the package at the opposite end portions of the package. The step of moving the package further comprises the step of linearly moving the package axially thereof for cutting the wrapper in the axial direction of the package.
The step of moving the package may comprise the step of linearly moving the package axially thereof while rotatingly moving the package about the central axis thereof for cutting the wrapper spirally.
In another embodiment, the method further comprises the step of sweeping the laser beam over the package which is held in position.
The step of sweeping the laser beam may comprise the step of linearly sweeping the laser beam axially of the package for cutting the wrapper in the axial direction of the package.
There is also provided an apparatus for opening a package. The apparatus comprises support means for supporting the package thereon at a fixed position. The apparatus further comprises a laser beam source for directing a laser beam to the wrapper and linearly sweeping the laser beam over the wrapper to cut the wrapper with the laser beam in the axial direction of the package.
In other embodiment, the apparatus further comprises guide means adapted to guide the support means for linearly movement axially of the package to cut the wrapper with the laser beam in the axial direction of the package.
In case of the package which is cylindrical, the support means may include guide means for guiding the package for rotatingly movement about the central axis thereof on the support means while directing the laser beam to the wrapper, to cut the wrapper circumferentially of the package at the opposite end portions of the package.
The support means may include first drive means for rotatingly moving the package about the central axis thereof on the support means while directing the laser beam to the wrapper, to cut the wrapper circumferentially of the package at the opposite end portions of the package. The apparatus may further comprise second drive means for linearly moving the support means axially of the package to cut the wrapper with the laser beam in the axial direction of the package.
In connection to the covering layer interposed between the content and the wrapper or between the layers of the content adjacent to the outer surface of the content, the apparatus may further comprise detector means for detecting the covering layer, and control means for controlling the first and second drive means in response to a signal from the detector means to direct the laser beam to the package at the position of the covering layer.
In other embodiment, the roll includes a web of paper wound thereon and an adhesive double coated tape which includes two adhesive layers formed on the opposite sides thereof and a release agent double coated paper adhered to one of the adhesive layers, the other adhesive layer being adhered to the end of the web. The adhesive double coated tape further includes a covering layer of material having a laser beam absorptivity which is lower than that of the wrapper for covering the roll from the laser beam to protect the roll from being damaged by the laser beam.
The adhesive double coated tape may be adhered to the end of the web all over the width thereof.
There is also provided an adhesive double coated tape comprising an elongated substrate. Two adhesive layers are formed on the opposite sides of the substrate. A release agent double coated paper is adhered to one of the adhesive layers. A covering layer is formed on one of the opposite sides of the release agent double coated paper, the covering layer being of material having a low absorptivity with respect to a type of laser beam.
The covering layer may be formed on one of the opposite sides of the substrate.
The type of laser beam may comprise CO2 laser beam. The covering layer may comprise a foil of metal such as aluminum.
The covering layer may be adhered to one of the opposite sides of the release agent double coated paper or the substrate.
The covering layer may be coated on one of the opposite sides of the release agent double coated paper or the substrate.
The covering layer may be vapour deposited on one of the opposite sides of the release agent double coated paper or the substrate.
The adhesive double coated tape may comprise an elongated substrate of material having a low absorptivity with respect to a type of laser beam.
The substrate may be made of metal such as aluminum.
In a preferred embodiment, the elongated substrate includes a portion weakened to be torn along a straight tearing line extending longitudinally of the substrate adjacent to one edge thereof. The substrate is free from one of the adhesive layers at least between the tearing line and the one edge of the substrate. An elongated void is formed in and clear of the other adhesive layer along the tearing line.